What is Strabismus?
by Dr. Jeffrey Cooper & Rachel Cooper (no relation). © 2001-2013
Does the Person Have Constant or Intermittent Strabismus?
This is one of the most important findings the eye doctor makes! It is important for you as a parent or patient to understand the difference between constant and intermittent strabismus. This distinction has great bearing on timing and types of treatment.
When the eye turn occurs at all distances and at all times, it is called constant strabismus. When the eye turn occurs only some of the time, it is called intermittent strabismus or alternating strabismus. With intermittent strabismus, the eye turn might be observed only occasionally, such as during stressful situations or when the person is ill. Please note that if the eye turn is constant at a certain
Up to the first 6 months of age, intermittent strabismus is a normal developmental milestone. After 6 months, it needs to be evaluated.
Treatment of Constant Strabismus
Constant turns are to be dealt with immediately if one wants to re-establish proper use of both eyes. Treatment for this condition should be early and aggressive. If the eye turn is constant and simple things like patching, drops, and/or glasses (bifocal, prismatic, etc) do not eliminate the eye turn, Vision Therapy, Orthoptics, or Surgery needs to be considered.
Keep in mind that ophthalmologists are eye surgeons and they infrequently offer or recommend Vision Therapy or orthoptics as treatment options. See Is Eye Muscle Surgery the Only Strabismus Treatment? For information on Vision Therapy or Orthoptics as treatment options, consult a developmental (or behavioral) optometrist.
Treatment of Intermittent Strabismus
With intermittent strabismus, the eye does not turn in all the time, so the brain is probably receiving adequate stimulation for the development of binocular vision.
After 6 months of age, this condition does need attention, but neither the eye doctor nor parent needs to panic. As long as the eyes are straight some of the time, the brain will develop normal functioning of the eyes (stereoscopic depth perception). Children with intermittent eye turns should be handled with judicious patching, special glasses, and/or Vision Therapy. Surgery, if considered at all, should be a last resort. See Eye Muscle Surgery as Treatment for Strabismus, including Intermittent Exotropia
A Parent's Choice re: Treatment for Intermittent Exotropia
Read what several parents have written regarding making the choice between Strabismus Eye Muscle Surgery or Vision Therapy for Intermittent Exotropia and Lazy Eye.
A Common Cause of Intermittent Exotropia (Intermittent Strabismus)
Convergence Insufficiency, if untreated, can cause intermittent exotropia (an outward eye turn that comes and goes).
Convergence Insufficiency (CI) is also the leading cause of eyestrain, blurry vision, double vision (diplopia), and/or headaches. A scientific study by the National Institutes of Health/National Eye Institute has concluded that the best treatment for convergence insufficiency is Vision Therapy in a clinical office with some home reinforcement. Learn more at What is Convergence Insufficiency Disorder?